1. Technical Field
Embodiments of the present disclosure generally relate to semiconductor integrated circuits and, more particularly, to semiconductor devices and semiconductor systems including the same.
2. Related Art
Mobile systems such as portable computers, personal digital assistants (PDAs) and portable phones have been developed to reduce the weight thereof for portability. Batteries supplying electric power to the mobile systems may largely affect the total weight of the mobile systems. If power consumption of semiconductor devices employed in the mobile systems is lowered, the capacity of the batteries may also be reduced to thus decrease the total weight of the mobile systems. Fast mobile systems are increasingly in demand with the development of multi-functional mobile systems. Accordingly, data transmission speeds of the semiconductor devices such as mobile memory devices (also, referred to as mobile memory chips) may be important factors in the determination of operation speeds of the high performance mobile systems.
Recently, the semiconductor devices have been designed to simultaneously receive command signals and address signals through ten pins. In such a case, the signals inputted through the ten pins include all information on the command signals and the address signals, and a command decoder and an address decoder decode the singles inputted through the ten pins to extract the command signals and the address signals.
In the case of synchronous semiconductor devices, the command signals and the address signals are inputted in synchronization with a clock signal. For example, double data rate (DDR) semiconductor devices receive the command signals and the address signals in synchronization with a rising edge and a falling edge of the clock signal, and single data rate (SDR) semiconductor devices receive the command signals and the address signals in synchronization with a rising edge of the clock signal.